Full Moon Concerts – Flower Moon.

On Thursday, I attended the Full Moon Concerts – Flower Moon, part of the Thursday Outsound music series at the Luggage Store Gallery in San Francisco (which I have played at many times). The series, which occurs on the Thursday closest to the full moon of every month, is curated by our friend Polly Moller.

The first half of the concert featured a duo by Theresa Wong and Kanoko Nishi. The set began with pitch extremes, high “harmonics” on the koto and low tones on the cello, at first quite distinct but converging and becoming more melodic over time. There were in fact three lines rather than two, as Wong’s vocals provided a counterpoint that was sometimes completely blended with the sound of the cello to form a chord, at other times a separate instrument. The overall sound moved from extremely percussive, with Nishi’s sometimes violent bending, striking and stretching of the strings and use of external objects such as styrofoam packing, to calm, almost “harmonic” drones. The transitions were not abrupt, but they did sometimes come unexpectedly, the listener suddenly finding himself in a completely different set of sounds. The last of these transitions went from a very loud section featuring the styrofoam and mallets set against a cello drone, and then suddenly fading out as quiet harmonics and blending into the city sounds outside.

The second half of the concert featured the ensemble Vorticella, which included Krystyna Bobrowski on horns, Erin Espeland on cello, Brenda Hutchinson on aluminum tube and vocals, and Karen Stackpole on percussion. The ensemble takes its from the vorticella, bell-shaped single-cell life forms that exist in colonies but can break off on their own at any time, an apt metaphor for group improvisation.

In taking notes for this review, I ended up drawing the following graph while listening, and I think it describes the initial section of the performance as well as any full text:

I particularly noticed how Hutchinson’s vocals as amplified and resonated by the tube sounded “electronic”, and my attention was focused on this as well as Stackpole’s metallic percussion, which ranged from conventionally “metallic sounding” to unusual squeaks and bubbling. Espeland’s cello and Bobrowski’s french horn and visually interesting kelp horns filled in the space, with either long drones or “pointed sounds” that matched the texture of the percussion and the vocals.

A later section that caught my interest were a smoother and more “linear” piece anchored by bowed gongs, with drones on the cello and horns, ending with the resonances of the gongs fading naturally. This was followed by a relatively soft section of discrete notes and hits, which came a sudden end and concluded the concert.

CatSynth pic: lissajous (chaos link)

Via matrixsynth:

Originally from gerald:

My cat loves the Lissajous this thing generates

So what is a “Lissajous”? it is actually short for Lissajous curves or Lissajous figures, a class of 2D (and 3D) curves describing complex harmonic functions, or more simply multi-dimensional sine curves. The following equations describe a general Lissajous curve on an x-y coordinate plane:

x = A sin(at + φ)
y = B sin(bt)

Most of the time, one leaves out the A and B, which case all the curves fall on a convenient unit square.

The most commonly described Lissajous curves set the phase term φ to π/2, i.e., a standard cosine function, and have a and b at integer ratios, like 1:2, 6:5, etc. You can think of these as natural harmonics, like in musical sounds. You can see a few of the graphs below, first for a=1 and b=2:

Here are 3:2 (a:b), and 9:8, respectively:

As you can see, the higher the ratio, the more complex and dense the figure. If you add all the figures up together, you should be able to fill the entire unit square.

There are all sorts of interesting special cases. For example, if you set a and b equal, you will get a circle. If you additionally set the φ to zero, you will get a straight line. Finally, you can mess with different values of φ, like 0.3 in the first drawing below, or set a and b to non-integer values, to get all sorts of interesting variations:

It is interesting to think about these sorts of functions by relating them both visually and aurally (i.e., synthesizing the corresponding waveforms), but we will leave that as an exercise for interested readers, perhaps returning to the topic in a future article.

Trying a little experiment. Trackposted to Gone Hollywood, Conservative Cat, The Crazy Rants of Samantha Burns, and The Pet Haven Blog, thanks to Linkfest Haven Deluxe. The links here and in the trackbacks do not necessarily reflect the opinions of this site or its contributors.